The proposed study is concerned with the antecedents, behavioral and psychological outcomes of orthognathic surgery. The first component will develop a measure of self-perceived need for surgery which distinguishes patients who elect surgery from those who do not. The second component will utilize this measure and other physiological, psychological and functional variables to predict the immediate short-term and long-term outcomes of orthognathic surgery. Variables were selected on the basis of a pilot study with 75 orthognathic patients assessed shortly before, shortly after and one month after surgery. Neuroticism and expectations emerged as significant predictors of post-op satisfaction and self-esteem. The proposed study will examine expectations systematically before surgery, together with neuroticism and other personality variables. It is hypothesized that self-esteem, both body-image and extroversion will change significantly across the six measurement, periods. Component I will include 50 surgery, 50 no-surgery patients, and a panel or oral surgeons and orthodontists to assess need for treatment. Component II will be comprised of 100 patients who will complete two questionnaires before surgery and form additional measures within 24 hours after sugery. A comparison group at 100 non-surgery orthodontic patients will complete four questionnaires at parallel times.